You’re describing the internet though. If two people meet in a public space and conspire to commit a crime, the public space isn’t fined. In the same way that if two people on Lemmy meet and then conspire to commit a crime, the space shouldn’t be fined. If OTOH the platform owner was made aware and didn’t take action, then yes that would be aiding a crime.
I am a time traveller and I was trying to throw you off my trail but I seem to have failed.